Molecular Mechanisms of Sex Determination in Flowering Plants

Sex determination in flowering plants encompasses a spectrum of reproductive strategies, from hermaphroditism through monoecy to dioecy. Underlying this diversity are molecular circuits that govern the fate of floral primordia towards stamen or carpel development. Central to this process are transcription factors, small RNAs and hormonal signals—particularly ethylene and gibberellins—that integrate genetic and environmental cues. In cucurbit species, for instance, allelic variation at loci encoding 1-aminocyclopropane-1-carboxylic acid synthase (ACS) enzymes directs ethylene production and thereby the arrest or promotion of specific floral organs. In persimmon, a Y-linked small RNA represses a homeodomain transcription factor, establishing dioecy through activation of gynoecium-promoting pathways and suppression of androecium genes. Across angiosperms, orthologous regulatory modules are often conserved, yet species-specific adaptations—such as epigenetic modulation of key determinants—have evolved to fine-tune sex expression. Advances in genomic and transcriptomic technologies have unveiled interconnected gene networks, revealing how MADS-box factors, growth-regulating families and hormonal pathways collaborate to specify floral sexuality. This mechanistic insight not only illuminates fundamental principles of plant development but also informs breeding strategies for yield optimisation in crops where flower sex ratio is a critical determinant of fruit set and quality.

Research from Nature Portfolio

No recent Nature Portfolio content available.

Molecular Mechanisms of Sex Determination in Flowering Plants publication trend

The graph below shows the total number of articles in molecular mechanisms of sex determination in flowering plants across all publications each year (not limited to Nature Index journals).

Technical terms

Dioecy: A reproductive system in which individual plants bear only male or only female flowers.

Monoecy: A condition in which male and female flowers occur separately on the same plant.

Hermaphrodite: A flower containing both functional male (stamen) and female (carpel) organs.

Transcription factor: A protein that binds specific DNA sequences to regulate gene expression.

miRNA (microRNA): A small non-coding RNA molecule that inhibits target gene expression post-transcriptionally.

Ethylene: A gaseous plant hormone that influences flower sex expression, among other developmental processes.

References

1. An miR164-resistant mutation in the transcription factor gene CpCUC2B enhances carpel arrest and ectopic boundary specification in Cucurbita pepo flower development. Journal of Experimental Botany (2023).
2. Gene Interactions Regulating Sex Determination in Cucurbits. Frontiers in Plant Science (2019).
3. A Conserved Ethylene Biosynthesis Enzyme Leads to Andromonoecy in Two Cucumis Species. PLOS ONE (2009).
4. Gene networks orchestrated by MeGI: a single‐factor mechanism underlying sex determination in persimmon. The Plant Journal (2019).